Hey Ralph, that looks to be a '38 "bent tank" CWC frame. I know it came on the Wards Hawthorne Zep and I believe you can find it on a Roadmaster or Western Flyer too. There are tanks that have a similar profile but the big difference is the tail end of the tank, how this one dips down considerably. Here's a picture of my '38 Zep for what you need. It's a 3-gill tank with a door on the A-side.